Tube and suture stent introducer system

ABSTRACT

A stent delivery system and method are provided. The stent delivery system includes an elongate shaft including a proximal portion, a distal portion, at least one lumen extending at least partially therethrough, and a stent receiving portion on the distal portion of the elongate shaft. A stent is positioned on the stent receiving portion of the elongate shaft, the stent having a first position and a second position. A proximal constraining member is positioned on a proximal end of the stent. A distal constraining member is positioned on a distal end of the stent. A restraining member disposed throughout a length of the elongate shaft and releasably engaged with at least one of the proximal constraining member and the distal constraining member, the restraining member having a proximal end and a distal end. The stent is in the first position, the distal restraining member applies an axial mechanical force to the distal constraining member.

RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 62/415,283 filed Oct. 31, 2016, which isincorporated by reference in its entirety.

BACKGROUND 1. Technical Field

This invention relates to a medical device, and in particular to amechanically expandable device for delivering and deploying a stent ordilation and a method of delivering and deploying the stent into a bodylumen.

2. Background Information

A self-expanding stent is typically introduced into the body using adelivery device that includes an outer sheath coaxially disposed andslidable over an inner catheter. The stent is disposed at the distal endof the device between the inner catheter and the outer sheath and heldin a compressed position by the outer sheath. The inner catheter and theouter sheath move coaxially with respect to each other. The stent may bedeployed by proximally pulling back the outer sheath relative to theinner catheter until the stent is exposed. The self-expanding stentexpands from the stent distal end to the stent proximal end as thesheath is proximally withdrawn.

Several problems may occur with the sheathed delivery device describedabove. The sheath release delivery devices are difficult to repositionor remove and slow to operate. The stent may only be partially deployedprior to reconstrainment of the stent by the sheath in order to stillreposition or remove the stent. Once the stent is fully deployed, i.e.radially expanded, the sheath cannot reconstrain the stent. For example,utilizing a conventional outer sheath/inner catheter delivery device maycause the physician to inadvertently use excessive force and pull backthe outer sheath too far, thereby prematurely deploying the stent in anincorrect position within a body lumen. At this step in the procedure,repositioning of the stent becomes difficult, if not impossible, becausethe stent has already radially self-expanded into the body lumen.Additionally, retraction of the outer sheath may not be achieved withcontrolled movement because the physician is manually retracting theouter sheath which may lead to uneven or inadvertent jerking back of theouter sheath that can lead to improper position of the stent.

Additionally, in a typical sheath release device where the outer sheathis proximally withdrawn, the first portion of the self-expanding stentto make contact with the body vessel is the most distal portion of thestent. This type of release may cause difficulty in accurately placingthe proximal portion of the stent because the distal end of the stent ispositioned first while the proximal portion of the stent is stillcovered by the outer sheath. Accurate placement of the proximal portionof the stent and/or the stent body may be important in certainapplications, for example to prevent stent migration or to properly opena stricture along the entire length of the stricture. An additionaldrawback occurs with the sheathed stent delivery system where directvisualization of the stent is required. For example, in endoscopicallyplaced stents, the sheath tends to prevent or obscure the location ofthe stent, making accurate placement of the stent more difficult.

Further potential drawbacks for the conventional sheathed stent deliverysystem involve the stent placement within the system prior to use withina patient. Loading and anchoring of a conventional sheathed stentdelivery device is an involved process that may require preloading thestent into the device so that the stent remains compressed within thesheath during shipment and storage prior to use in the patient. Extendedcompression of the stent may lead to an alteration in the stentmechanical properties.

Conventional sheathed stent delivery devices also require a high forceto overcome the friction between the stent and the sheath that may alsobe a problem for proper stent placement within the patient. Theintroducer must be mechanically stronger to overcome the frictionalforces to avoid undesirable frictional consequences such as stretchingof the introducer catchers and hysterics in the movement of the stent.The sheathed stent delivery device also requires more space within anendoscope compared to a sheathless device and also adds additionalexpense to the delivery system.

Accordingly, in view of the drawbacks of current technology, there is adesire for a mechanically expandable delivery system and dilation systemthat can increase the control, accuracy and ease of placement of a stentduring deployment of the stent within a patient or dilation of a lumenwithin a patient. The delivery system would ideally reduce the risk ofmalfunction while providing for a smoother, more accurate and quickerdeployment of the entire stent. The delivery system also would providethe ability to reconstrain, recapture, reposition and/or remove thestent after expansion of the stent.

BRIEF SUMMARY

Accordingly, it is an object of the present invention to provide adevice and a method having features that resolve or improve on one ormore of the above-described drawbacks.

The foregoing object is obtained in one aspect of the present inventionby providing a stent delivery system. The stent delivery system includesan elongate shaft including a proximal portion, a distal portion, atleast one lumen extending at least partially therethrough, and a stentreceiving portion on the distal portion of the elongate shaft. A stentis positioned on the stent receiving portion of the elongate shaft, thestent having a first configuration and a second configuration. Aproximal constraining member is positioned on a proximal end of thestent. A distal constraining member is positioned on a distal end of thestent a restraining member disposed throughout a length of the elongateshaft and releasably engaged with at least one of the proximalconstraining member and the distal constraining member, the restrainingmember having a proximal end and a distal end. When the stent is in thefirst configuration, the distal restraining member applies an axialmechanical force to the distal constraining member.

In another aspect of the present invention, a method of implanting astent in a patient's lumen is provided. The method includes inserting adistal portion of a stent delivery system into a lumen of a patient, thestent delivery system comprising: an elongate shaft including a proximalportion, a distal portion, at least one lumen extending at leastpartially therethrough, and a stent receiving portion on the distalportion of the elongate shaft. A stent is positioned on the stentreceiving portion of the elongate shaft, the stent having a firstconfiguration and a second configuration. A proximal constraining memberis positioned on a proximal end of the stent. A distal constrainingmember is positioned on a distal end of the stent. A restraining memberis disposed throughout the length of the elongate shaft and releasablyengaged with the distal constraining member, the distal restrainingmember having a proximal end and a distal end. A release wire isdisposed through the elongate shaft and releasably engaged with theproximal constraining member and the distal restraining member. Themethod includes holding the stent in the first configuration withlongitudinal tensile force applied to the stent by the restrainingmember and tensioning the stent for delivery of the stent to an implantsite. The method includes positioning the stent at the implant site andexpanding the distal end of the stent by manipulating the restrainingmember in a proximal direction and releasing longitudinal force on thestent. The method further includes releasing the release wire and thedistal constraining member from the stent.

In another aspect of the present invention, a system is provided. Thesystem includes an elongate shaft including a proximal portion, a distalportion, at least one lumen extending at least partially therethrough,and a stent receiving portion on the distal portion of the elongateshaft. A sheath is positioned longitudinally around the elongate shaft,the elongate shaft extending coaxially at least partially within thelumen of the sheath, the sheath moveably positionable relative to theelongate shaft. A stent is positioned on the stent receiving portion ofthe elongate shaft, the stent having a first configuration and a secondconfiguration. A proximal constraining member is positioned on aproximal end of the stent. A distal constraining member is positioned ona distal end of the stent, the distal constraining member comprising apair of grasping loops. A distal restraining member is disposedthroughout the length of the elongate shaft and releasably engaged withthe distal constraining member, the distal restraining member having aproximal end and a distal end. When the stent is in the firstconfiguration, the distal restraining member applies an axial mechanicalforce to the distal constraining member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B illustrate a stent delivery system 10 in accordance withembodiments of the present invention.

FIG. 2 illustrates a sectional view of the stent delivery system shownin FIG. 1.

FIG. 3. illustrates a distal end of the stent delivery system shown FIG.1.

FIGS. 4A and 4B illustrate a first section of the distal end of thestent delivery system shown in FIGS. 1A and 1B.

FIG. 5 illustrates the second section of the distal end of the stentdelivery system shown in FIGS. 1A and 1B.

FIG. 6 illustrates an embodiment of a proximal end of the stent of thestent delivery system.

FIG. 7 illustrates a cross-section through an inner tube of the of thestent delivery system.

FIG. 8 illustrates an alternative embodiment a stent delivery system inaccordance with embodiments of the present invention.

FIGS. 9A and 9B illustrate a side view of the stent delivery systemshown in FIG. 8.

FIGS. 10A-10C illustrate a distal end of the stent delivery system ofFIG. 8.

FIG. 11 illustrates a proximal end of the stent delivery system of FIG.8.

FIG. 12 illustrates a sectional view of the stent delivery system ofFIG. 8.

FIG. 13A and FIG. 13B illustrates operation of the stent delivery systemof FIG. 8.

FIG. 14 illustrates a sectional view of an alternate embodiment of astent delivery system.

FIG. 15 illustrates a cross-section through an outer shaft of anembodiment of a stent delivery system.

FIG. 16 is a sectional view of the embodiment of the system of FIG. 14.

FIGS. 17A-17C illustrate operation of the embodiment of the system ofFIG. 14.

FIG. 18 illustrates of an alternative embodiment of a handle assembly ofa stent delivery system.

FIG. 19 is a schematic view of the handle assembly of FIG. 18.

FIGS. 20A and 20B illustrate operation of the embodiment of the handleassembly of FIG. 18.

FIG. 21 illustrates of schematic view of an alternative embodiment of ahandle assembly of a stent delivery system.

FIGS. 22A and 22B illustrate operation of the embodiment of FIG. 21.

FIG. 23 illustrates of schematic view of an alternative embodiment of ahandle assembly of a stent delivery system.

FIGS. 24A-24C illustrate operation of the embodiment of the system ofFIG. 23.

FIG. 25 illustrates a cross-section through an alternative outer shaftof the present invention.

FIG. 26 illustrates a schematic view of an alternative embodiment of ahandle assembly of a stent delivery system.

FIG. 27 illustrates operation of this embodiment of the system of FIG.26.

DETAILED DESCRIPTION OF THE DRAWINGS AND THE PRESENTLY PREFERREDEMBODIMENTS

The invention is described with reference to the drawings in which likeelements are referred to by like numerals. The relationship andfunctioning of the various elements of this invention are betterunderstood by the following detailed description. However, theembodiments of this invention are not limited to the embodimentsillustrated in the drawings. It should be understood that the drawingsare not to scale, and in certain instances details have been omittedwhich are not necessary for an understanding of the present invention,such as conventional fabrication and assembly.

As used in the specification, the terms proximal and distal should beunderstood as being in the terms of a physician delivering the stent toa patient. Hence the term “distal” means the portion of the deliverysystem that is farthest from the physician and the term “proximal” meansthe portion of the delivery system that is nearest to the physician.

FIG. 1A illustrates a stent delivery system 10 in accordance withembodiments of the present invention. The stent delivery system 10includes an inner shaft 22 and a handle 26 at a proximal portion 27 ofthe system 10. A stent 28 is positionable on a stent region 30 of theinner shaft 22 at a distal portion 31 of the delivery system 10. Asshown, the stent 28 is in an expanded configuration 66. The stentdelivery system 10 may optionally include an outer sheath slidablypositionable over a portion the inner shaft 22 to cover the stent region30 and the stent 28. The stent delivery system 10 may also include aguidewire extendable through a port of the inner shaft 22 through adistal tip 41 at the distal portion 31 of the delivery system 10. Thestent 28 may be placed in a constrained position, as shown in FIG. 1B.

FIG. 2 illustrates a sectional view of the stent delivery system 10shown in FIG. 1. As shown in FIG. 2, the stent 28 is in an expandedconfiguration 66 while still connected to the inner shaft 22. In someembodiments, the stent 28 may be a self-expanding stent. The stent 28may be any kind of stent that has a tendency to radially collapse when alongitudinal force is applied to the ends of the stent. By way ofnon-limiting example, the stent 28 may be formed as a woven mesh formedfrom a metal or polymer or a laser cut pattern formed in a metal stent.The stent 28 may also be formed from a bioabsorbable material. Oneexample of a woven stent is the EVOLUTION® stent (Wilson-Cook Medical,Inc.). The stent 28 is held in the constrained configuration 40 by amechanism that may be provided with or without an outer sheath. In oneembodiment that is described in detail below, that includes a proximalstent constraining member 44 and a distal stent constraining member 46to longitudinally constrain the stent 28 and hold the stent 28 collapsedagainst the inner shaft 22. The proximal and distal stent constrainingmembers 44, 46 are operably connected to the handle 26. In particular,the distal stent constraining member 46 is connected to the handle via arestraining member disposed through a port in the inner shaft 22. Therestraining member 56 includes a proximal end 58 and a distal end 57.The restraining member 56 is releaseably connected to the distalconstraining member 46. The proximal end 58 of the restraining member 56is connected to the handle 26 of the stent delivery system 10. Therestraining member 56 is configured to allow the user to move the distalend 33 of the stent 28 from a constrained configuration 40 (as shown inFIG. 1B) to an expanded configuration 66 without fully deploying thestent. The proximal stent constraining member 44 is connected to thehandle 26 via release wire 59. The release wire 59 includes a distal end60 and a proximal end 61. The proximal end 61 of the release wire 59 isconnected to the handle 26 on a proximal end of the stent deliverysystem 10. As shown in the figures, the release wire releasably engagesthe proximal constraining member and releasably connects the proximalend of the stent to the inner shaft 22. The distal end 60 of the releasewire 59 engages the distal end 57 of the restraining member 56 andreleasably connect the distal end 60 of the release wire 59 to the innershaft 22. As shown in FIG. 2, the stent 28 is held compressed againstthe inner shaft 22 by the proximal and distal stent constraining members44, 46 in a first position 47 applying longitudinal force to the stent28 in opposite directions. When present, an outer sheath may providesome compressive force to the stent in addition to the proximal anddistal constraining members 44, 46.

FIG. 3. shows a view of the distal end of the system 10. As shown, thestent 28 is shown in an expanded configuration 66 in FIG. 3 where thestent 28 is expanded away from the inner shaft 22. The distalconstraining members 46 is in a second position 49 and remain connectedto the stent 28 but the longitudinal force on the stent 28 has beenremoved to allow the stent 28 to expand. The distal constraining member,in this embodiment, includes a pair of distal grasping loops 48, 50. Thedistal grasping loops 48, 50 may be interwoven through one or more peaksof the stent so that the distal grasping loops 48, 50 when pulled tautwill collapse the peaks 29 of the stent 28 onto the inner shaft 22. Thedistal grasping loops 48, 50 may be positioned on opposing sides of thestent 28, as provided in this embodiment. In alternative embodiments,the grasping loops 48, 50 may be placed in different positions. Thedistal grasping loops 48, 50 of the distal constraining member 46 may beanchored at one or more points to better secure the stent 28 on theinner shaft 22. In other embodiments, the stent 28 may include a sutureabout the proximal end 31 and the distal end 33 of the stent 28. Thegrasping loops may be interwoven about the suture at the ends of thestent 28. In the embodiment shown in FIG. 3, the distal grasping loops48, 50 are configured to remain attached to the stent 28 upon deploymentwithin the lumen of a patient. In alternative embodiments, the distalgrasping loops 48, 50 may be configured to be released from the stentupon deployment within the lumen of a patient.

As shown, the restraining member 56 extends within a first opening 23disposed in the inner shaft 22 and exits from the port 38 at a distalend 24 of the inner shaft 22. In this embodiment, the restraining member56 is a suture. One of skill in the art will understand other materialsmay be suitable for the restraining member 56. The restraining member 56is configured to keep the distal end 33 of the stent 28 attached to theinner tube 22 prior to deployment within the lumen of a patient whileallowing the stent 28 to be released from the constrained configuration40 to the expanded configuration 66. As shown, the restraining member 56exits from a port 38 at the distal end 24 of the inner shaft 22. In thisembodiment, the restraining member 56 extends in a proximal directionand engages with a distal point 51 of the distal grasping loops 48, 50of the distal constraining member 46. After exiting the distal graspingloops 48, 50 of the distal constraining member 46, the restrainingmember 56 extends in a distal direction and enters into a suture lumen34 of inner tube 22 of the system 10 near the distal tip 41 of thesystem 10. Upon entering the lumen 34 of the inner tube 22 of the system10, the restraining member 56 extends through the length of the innertube 22 and engages with a handle 26. The handle 26 allows for controlof the restraining member 56 in order to move the stent 28 from theconstrained configuration 40 to the expanded configuration 66 so thatthe release of the tension on the stent 28 is uniform within thepatient's lumen. The restraining member 56 moves the distal end 33 ofthe stent 28 so that the longitudinal tension exerted on the stent 28 isrelaxed when the distal grasping loops of the distal constraining member44 are further apart and the stent 28 expands uniformly due to theuniform release of the tension on the stent 28 by the distalconstraining member 46.

The stent 28 may be repeatedly moved between the constrainedconfiguration 40 and the expanded configuration 66 by manipulating therestraining member either in a proximal direction or a distal directionuntil the stent is properly positioned. With the stent repositioned inthe constrained configuration 40, an outer sheath may be repositionedover the stent 28 as shown in FIG. 2 and the stent 28 may even bewithdrawn from the patient, for example if an incorrect size of stentwas originally selected. The stent configurations may be changedmultiple times within the patient for repositioning or removal until theproximal and distal constraining members 44, 46 are released fromconnection with the stent 28 as described below.

FIGS. 4A and 4B illustrate the first section 42 of the distal end 24 ofthe system 10. As shown, the system 10 includes a distal tip 41, aninner shaft 22, a distal end portion 57 of the restraining member 56,and a distal end portion 60 of the release wire 59. The inner tube 22includes an opening 23, where the distal end portion 57 of therestraining member 56 and the distal end portion 60 of the release wire59 are disposed. The release wire 59 is releasably engaged within alumen of the inner tube 22 and terminates proximal to the distal tip 41of the system 10. In this embodiment, the distal end portion 57 of therestraining member 56 is anchored to the inner tube 22 by the releasewire 59. The proximal portion the release wire (not shown) is engagedwith a handle of the system. As will be discussed below, upon release ofthe release wire 59 by the user of the system 10, the proximal end ofthe restraining member is also released, allowing the distal end 33 ofthe stent 28 to be deployed within the lumen of the patient. In thisembodiment, the restraining member 56 is a looped suture. In alternativeembodiments, the restraining member 56 may have alternativeconfigurations or materials, including a single suture. The release wire59 may be frictionally engaged with a portion of the inner tube 22 ofthe system 10 to hold the release wire 59 in position until the stent 28is in the proper position for release as discussed above. The releasewire 59 may be proximally withdrawn to release the distal constrainingmember 46.

As shown in FIG. 4B, the system 10 includes an inner shaft 22, distaltip 41, and a distal end portion 57 of the restraining member 56. Theinner shaft 22 further includes access to the suture lumen 34 of theinner tube 22 of the system 10. In this embodiment, the opening 23 inthe inner shaft 22, where the distal end portion 57 of the restrainingmember 56 and the distal end portion 60 of the release wire 59 aredisposed, is also visible. The release wire 59 is releasably engagedwithin a port 38 of the inner tube 22 and terminates proximal to thedistal tip 41 of the system 10. The restraining member 56 enters intothe inner tube 22 at a port 39 distal to the stent 28 and proximal ofthe distal tip 41. The second opening 39 is disposed distal to the firstport 38 on the distal end of the system. As discussed above, therestraining member 56 enters into this second port 39 and extends to ahandle, which allows for a user to manipulate the position of the distalend 33 of the stent 28.

FIG. 5 illustrates the second section 43 of the distal end 24 of thesystem 10. As shown, the system 10 includes a distal tip 41, an innershaft 22, a distal end portion 57 of the restraining member 56, and adistal end portion 60 of the release wire 59. The distal end 57 ofrestraining member 56, in this embodiment, is engaged with the graspingloops 48, 50 of the distal constraining member 46. As shown, thegrasping loops 48, 50 of the distal constraining member are positionedon a distal end 33 of the stent 28. The stent 28 is still connected tothe inner shaft 22 of the system 10 by the restraining member 59.

The materials used to manufacture the components of the stent deliverysystems and mechanical dilator systems described herein may be anymaterials known to one skilled in the art that are suitable for use inpatients. By way of non-limiting example, the shafts and sheaths may beformed from polytetrafluorothylene (PTFE) particularly when a lowfriction outer sheath is desirable. Nylon and HDPE may also be used forclarity. Additional possible materials include, but are not limited tothe following, polyethylene ether ketone (PEEK), fluorinated ethylenepropylene (FEP), perfluoroalkoxy polymer resin (PFA), polyamide,polyurethane, high density or low density polyethylene, and nylonincluding multi-layer or single layer structures and the like and mayalso include reinforcement wires, braid wires, coils, coil springs andor filaments. The stent may be formed from but is not limited to thefollowing materials: Nickel titanium alloys, for example, nitinol,stainless steel, cobalt alloys and titanium alloys. The loops of theconstraining members may be made from common suture material as known inthe art, for example polyester suture such as 4-0 Tevdek®, nylon, silk,polypropylene, ultra-high molecular weight polyethylene (UHMPE) and thelike. The sutures may be monofilament, braided, twisted ormultifilament. The loops and the retaining wires may also be made from ametallic alloy such as stainless steel or nickel titanium. In someembodiments, the stent, the loops and/or the retaining wires may be madefrom biodegradable materials. A number of bioabsorbable homopolymers,copolymers, or blends of bioabsorbable polymers are known in the medicalarts. These include, but are not necessarily limited to, polyestersincluding poly-alpha hydroxy and poly-beta hydroxy polyesters,polycaprolactone, polyglycolic acid, polyether-esters,poly(p-dioxanone), polyoxaesters; polyphosphazenes; polyanhydrides;polycarbonates including polytrimethylene carbonate andpoly(iminocarbonate); polyesteramides; polyurethanes; polyisocyantes;polyphosphazines; polyethers including polyglycols polyorthoesters;expoxy polymers including polyethylene oxide; polysaccharides includingcellulose, chitin, dextran, starch, hydroxyethyl starch, polygluconate,hyaluronic acid; polyamides including polyamino acids, polyester-amides,polyglutamic acid, poly-lysine, gelatin, fibrin, fibrinogen, casein,collagen.

FIG. 6 illustrates an embodiment of a proximal end 32 of the stent 28 ofthe system 10. As shown, the stent 28 is shown in an expandedconfiguration 66. The proximal constraining member 44 may comprise oneor more distal grasping loops 52, 54. In this embodiment, the proximalconstraining member 44 comprises two loops 52, 54 that are interwoventhrough one or more peaks 29 of the stent 28 so that when pulled taut,the proximal constraining member 44 will collapse the peaks 29 of thestent 28 onto the inner shaft 22. The proximal grasping loops 52, 54 ofthe proximal constraining member 44 may be anchored at one or morepoints to better secure the stent 28 on the inner shaft 22. In theembodiment shown in FIG. 6, the proximal grasping loops 52, 54 areconfigured to remain attached to the stent 28 upon deployment within thelumen of a patient. In alternative embodiments, the proximal graspingloops 52, 54 may be configured to be released from the stent 28 upondeployment within the lumen of a patient. The proximal end 32 of thestent 28 remains connected to the inner shaft 22 even in the expandedconfiguration when the release wire 59 is engaged in the proximalgrasping loops 52, 54 of the proximal constraining member 44. As shown,the release wire 59 extends within the inner shaft 22 and engages thetwo proximal grasping loops 52, 54 of the proximal constrainingarrangement 44. In this embodiment, the proximal end 32 of the stent 28is released from the constrained configuration 40 to the expandedconfiguration 66 by manipulation of a sheath.

In an alternative embodiment, the system 10 may include a secondrestraining member engaged with the proximal grasping loops of theproximal constraining member. In this alternative embodiment, therestraining member extends within a port disposed in the inner shaft andexits from the port at a proximal end of the inner shaft. Therestraining member is configured to keep the distal end of the stentattached to the inner tube prior to deployment within the lumen of apatient while allowing the stent 28 to be released from the constrainedconfiguration 40 to the expanded configuration 66. The proximal endstent 28 is released from the constrained configuration 40 to theexpanded configuration 66 by manipulation in response to the proximaland distal manipulation of the second restraining member by the user ofthe system. In alternative embodiments, a second retaining member may beincluded in the system. The second restraining member may engage theproximal constraining member. In these embodiments, the secondconstraining member is configured to keep the proximal end of the stentattached to the inner tube prior to deployment within the lumen of apatient while allowing the stent 28 to be released from the constrainedconfiguration 40 to the expanded configuration 66. The stent 28 isreleased from the constrained configuration 40 to the expandedconfiguration 66 by manipulation in response to the proximal and distalmanipulation of the restraining member by the user of the system.

FIG. 7 illustrates a cross-section through an inner tube 22 of the ofthe stent delivery system 10. In this embodiment, the system 10 isprovided in an over-the-wire configuration. In this over the wireconfiguration, the cross-section throughout the inner tube 22 is thesame throughout its length. The inner tube 22 includes a suture lumen34, a first lumen 72, and a second lumen 74. The suture lumen 34, thesecond lumen 72, and the third lumen 74 are disposed through the entirelength of the inner tube 22. The suture lumen 34 may be used tofacilitate the introduction of a medical device, such as a guidewire.The second lumen 72 is provided to receive at least a portion of therestraining member 56. The third lumen 74 is provided and is configuredto receive a release wire 59 for use with the system 10. Each of thesuture lumen 34, the second lumen 72, and the third lumen 74 areaccessible from the proximal end 25 of the inner shaft 22. Exemplarymaterials for forming the shaft include, but are not limited to, metalalloys such as stainless steel, tantalum or its alloys, tungsten,platinum, gold, copper, palladium, rhodium, or a superelastic alloys,such as nitinol or polymers that can be provided with sufficient shorehardness, such as Pebax, Peek, polyimide, liquid crystal polymers (LCP)such as Vectran, polyethylene, polyethylene terephthalate and Nylon. Inalternative embodiments, the inner tube 22 may further includeadditional lumens. In one embodiment, a fourth lumen may be includedwithin the inner tube 22. In this embodiment, the fourth lumen may beused to provide a conduit for a second restraining member for theproximal constraining member 44 of the stent 28.

FIG. 8 illustrates an alternative embodiment of a stent delivery system110 in accordance with embodiments of the present invention. The stentdelivery system 110 includes an inner shaft 122 and a handle 126 at aproximal portion 125 of the system 110. A stent 128 (shown in FIG. 2) ispositionable on a stent region 130 of the inner shaft 122 shaft 122 at adistal portion 131 of the delivery system 110. The stent delivery system110 includes an outer sheath 112 slidably positionable over a portionthe inner shaft 122 to cover the stent region 130 and the stent 128. Thestent delivery system 110 may also include a guidewire extendablethrough a port of the inner shaft 122 through a distal tip 141 at thedistal portion 131 of the delivery system 110. The handle 126 iscomprised of at least two parts: a sheath shuttle 163 that isoperatively connected to the outer sheath 112 and a constraining shuttle165.

FIG. 9A illustrates a side view of the stent delivery system 110 shownin FIG. 8. As shown in FIG. 9A, the stent 128 is in a constrainedconfiguration collapsed against the inner shaft 122. As shown, thesheath 112 is disposed over the stent 128 has been withdrawn proximallyin order to provide a detailed look of the stent 128 in the constrainedconfiguration 140. In some embodiments, the stent 128 may be aself-expanding stent. The stent 128 may be any kind of stent that has atendency to radially collapse when a longitudinal force is applied tothe ends of the stent. By way of non-limiting example, the stent 128 maybe formed as a woven mesh formed from a metal or polymer or a laser cutpattern formed in a metal stent. The stent may also be formed from abioabsorbable material. One example of a woven stent is the EVOLUTION®stent (Wilson-Cook Medical, Inc.). The stent 128 is held in theconstrained configuration 140 by a mechanism that may be provided withor without an outer sheath 112. In one embodiment, that is described indetail below, that includes a proximal stent constraining arrangement144 and a distal stent constraining arrangement 146 to longitudinallyconstrain the stent 128 and hold the stent 128 collapsed against theinner shaft 122. The proximal and distal stent constraining arrangements144, 146 are operably connected to the constraining shuttle 165 of thehandle 126. In particular, the proximal constraining arrangement 144 andthe distal constraining arrangement 146 is connected to the handlethrough at least one port in the inner shaft 122, where a release wire(not shown) is disposed therethrough. As shown in FIG. 9A, the stent 128is held compressed against the inner shaft 122 by the proximal anddistal stent constraining members 144, 146 in a first position 147applying longitudinal force to the stent 128 in opposite directions.

The stent 128 is shown in an expanded configuration 166 in FIG. 9B wherethe stent 128 is expanded away from the inner shaft 122. The proximaland distal constraining assemblies 144, 146 are in a second position 149and remain connected to the stent 128 but the longitudinal force on thestent 128 has been removed to allow the stent 128 to expand. This secondposition 149 of the proximal constraining arrangement 144 and distalconstraining arrangement 146 is achieved by manipulating a handleattached to the proximal constraining arrangement and the distalconstraining arrangement 146 in a proximal direction.

FIG. 10A shows a view of a first side of the distal end of the system110. As shown, the stent 128 is shown in an expanded configuration 166in FIG. 10 where the stent 128 is expanded away from the inner shaft122. The distal constraining arrangement 146 is in a second position 149and remain connected to the stent 128 but the longitudinal force on thestent 128 has been removed to allow the stent 128 to expand. As shown,the first and second distal restraining loops 148, 150 extend from afirst opening 123 at the distal end 133 of the inner shaft 122. Thefirst and second distal restraining loops 148, 150 are engaged aretethered to the inner tube 122 by a release wire 159. The proximalportion of the release wire (not shown) is engaged with the handle 126of the system 110. In this embodiment, the first distal restraining loop148 extends in a proximal direction and is interwoven with the peaks ofthe distal end 133 of the stent 128. After traversing the peaks of thestent 128, the first distal restraining loop 148 exits the distal end133 of the stent and extends in a distal direction toward the distal tip141 of the system 110. Similarly, the second distal restraining loop 150extends in a proximal direction and is interwoven with the peaks of thedistal end 133 of the stent 128. After traversing the peaks of the stent128, the second distal restraining loop 150 exits the distal end 133 ofthe stent 128 and extends in a distal direction toward the distal tip141 of the system 110. In this embodiment, the distal constrainingarrangement 146, in this embodiment, includes a first distal loop 148,and a second distal loop 150. The distal loops 148, 150 may beinterwoven through one or more peaks of the stent so that the distalloops 148, 150 when pulled taut will collapse the peaks of the stentonto the inner shaft. The distal grasping loops may be positioned onopposing sides of the stent, as provided in this embodiment. Inparticular, the first distal loop 148 is interwoven through six peaks ofone side of the distal end 133 of the stent 128 halfway around the stentcircumference. The second distal loop 150 is interwoven through sixpeaks 129 of the distal end 133 of the stent 128 on the side opposite ofthe first distal loop 148 halfway around the circumference.

Upon release of the release wire 159 by the user of the system 110, thefirst distal restraining loop 148 and the second distal restraining loop150 is also released, allowing the distal end 133 of the stent 128 to bedeployed within the lumen of the patient. The release wire 159 may befrictionally engaged with a portion of the inner shaft 122 of the system110 to hold the release wire 159 in position until the stent 128 is inthe proper position for release. The first distal restraining loop 148and the second distal restraining loop 150 moves the distal end 133 ofthe stent 128 so that the longitudinal tension exerted on the stent 128is relaxed when the first distal restraining loop 148 and the seconddistal restraining loop 150 of the distal constraining arrangement 146are farther apart and the stent 128 expands uniformly due to the uniformrelease of the tension on the stent 128 by the distal constrainingarrangement 144.

FIG. 10B shows a view second side of the distal end of the system 110.As shown in this embodiment, a second opening 135 proximal to the distaltip 141 is in communication with a suture lumen 134 of the inner shaft122. The second opening 135 is positioned on an opposite side of theinner shaft 122 than the first opening 123. The first distal restrainingloop 148 enters into a suture lumen 134 of inner tube 122 of the system110 through the second opening 135 of the inner shaft. Upon entering thelumen 134 of the inner tube 122 of the system 110, the first distalrestraining loop 148 extends through the length of the inner tube 122and engages with a handle 126. The constraining shuttle 165 of thehandle 126 allows for control of the distal constraining assembly memberin order to move the stent 28 from the constrained configuration 140 tothe expanded configuration 166 so that the release of the tension on thestent 128 is uniform within the patient's lumen. Similarly, the seconddistal restraining loop 150 enters into the suture lumen 134 of innertube 122 of the system 110 through the second opening 135 of the innershaft 122. Upon entering the suture lumen 134 of the inner tube 122 ofthe system 110, the second distal restraining loop 150 extends throughthe length of the inner tube and engages with a handle 126.

FIG. 10C shows an alternative arrangement for the distal constrainingarrangement 146. In this embodiment, the distal constraining arrangement146, in this embodiment, includes a first distal loop 148, and a seconddistal loop 150. The distal loops 148, 150 may be interwoven through oneor more peaks of the stent so that the distal loops 148, 150 when pulledtaut will collapse the peaks of the stent onto the inner shaft. Thedistal grasping loops may be positioned on opposing sides of the stent,as provided in this embodiment. In particular, the first distal loop 148is interwoven through eight peaks of one side of the distal end 133 ofthe stent 128 halfway around the stent circumference. The second distalloop 150 is interwoven through six peaks of the distal end 133 of thestent 128 on the side opposite of the first distal loop 148 halfwayaround the circumference.

FIG. 11 shows a view of the proximal end of the system 10. As shown, thestent 128 is shown in an expanded configuration 166 in FIG. 11 where thestent 128 is expanded away from the inner shaft 122. The proximalconstraining arrangement 144 is in a second position and remainsconnected to the stent 128 but the longitudinal force on the stent 128has been removed to allow the stent 128 to expand. The proximalconstraining arrangement 144, in this embodiment, includes a firstproximal loop 152, and a second distal loop 154. The proximal loops 152,154 may be interwoven through one or more peaks of the stent so that theproximal loops 152, 154 when pulled taut will collapse the peaks of thestent 128 onto the inner shaft 122. The proximal restraining loops 152,154 may be positioned on opposing sides of the stent 128, as provided inthis embodiment. In particular, the first proximal loop 152 isinterwoven through six peaks of one side of the proximal end 132 of thestent 128 halfway around the circumference. The second proximal loop 154is interwoven through six peaks of the proximal end 132 of the stent 128on the side opposite of the first proximal loop 152 halfway around thecircumference. In alternative embodiments, the first proximal loop 152and the second proximal loop 154 may be interwoven through more peaks ofthe stent 128 or fewer peaks of the stent 128.

As shown, the first proximal loop 152 and the second proximal loop 154are tethered to the inner shaft 122 by a release wire 159. The proximalportion of the release wire (not shown) is engaged with a handle 126 ofthe system 110. The release wire 159 may be proximally withdrawn torelease the first proximal loop 152 and the second proximal loop 154. Inthis embodiment, the first proximal restraining loop 152 extends in aproximal direction and is interwoven with the peaks of the proximal end132 of the stent 128. After traversing the peaks of the stent 128, thefirst proximal restraining loop 152 exits the proximal end 132 of thestent 128 and extends in a proximal direction toward the handle 126 ofthe system. The first proximal restraining loop 152 enters into a suturelumen 134 of inner tube 122 of the system 110. Upon entering the lumen134 through an opening 136 of the inner shaft 122 of the system 110, thefirst proximal restraining loop 152 extends through the inner tube 122and engages with the constraining shuttle 165 of the handle 126. Thehandle 126 allows for control of the proximal constraining arrangement144 in order to move the stent 128 from the constrained configuration140 to the expanded configuration 166 so that the release of the tensionon the stent 128 is uniform within the patient's lumen.

Similarly, the second proximal constraining loop 154 extends in a distaldirection and is interwoven with the peaks of the proximal end 132 ofthe stent 128. After traversing the peaks of the stent 128, the secondproximal restraining loop 154 exits the proximal end 132 of the stent128 and extends in a proximal direction toward the handle 126 of thesystem 110. The second proximal constraining loop 154 enters into asuture lumen 134 of inner tube of the system through an opening of theinner shaft 122. Upon entering the lumen 134 of the inner tube 122 ofthe system 110, the second proximal constraining loop 154 extendsthrough the inner tube 122 and engages with the constraining shuttle 165of the handle 126. Upon release of the release wire 159 by the user ofthe system 110, the proximal end of the restraining member is alsoreleased, allowing the proximal end 132 of the stent 126 to be deployedwithin the lumen of the patient. The release wire 159 may befrictionally engaged with a portion of the inner shaft 122 of the system110 to hold the release wire 159 in position until the stent 128 is inthe proper position for release. The first proximal loop 152 and thesecond proximal loop 154 moves the proximal end 132 of the stent 128 sothat the longitudinal tension exerted on the stent 128 is relaxed whenfirst proximal loop 152 and the second proximal loop 154 of the proximalconstraining member 144 are farther apart and the stent 128 expandsuniformly due to the uniform release of the tension on the stent 28 bythe distal constraining member 44.

FIG. 12 is a schematic view of an embodiment of the present invention.The stent delivery system 110 includes an inner shaft 122 and a handle(not shown) at a proximal portion 127 of the system 110. A stent 128 ispositionable on a stent region 130 of the inner shaft 122 at a distalportion 131 of the delivery system 110. The stent 128 is shown in anexpanded position. As shown, the proximal and distal stent constrainingarrangements 144, 146 are operably connected to the handle 126 and aredisposed through the suture lumen 134. The stent delivery system 110 mayalso include a guidewire extendable through a second lumen 172 of theinner shaft 122 through a distal tip 141 at the distal portion 131 ofthe delivery system 110. A release wire is disposed in through the thirdlumen 174 and is engaged with a portion of the proximal and distalconstraining arrangements 144, 146 to anchor the proximal and distalconstraining arrangements 144, 146 to the inner shaft 122.

Operation of an embodiment of the system is illustrated in FIG. 13A andFIG. 13B. For ease of depiction, the stent 128 is not shown. In FIG.13A, the system includes an inner shaft 122 and a handle 126 at aproximal portion 127 of the system 110. The handle 126 includes aconstraining shuttle 165 and a sheath shuttle 167. A sheath 112 isoperably connected to the sheath shuttle 167 of the handle 126. Asshown, the proximal and distal stent constraining arrangements 144, 146are operably connected to the constraining handle 165 and are disposedthrough the suture lumen 134. The sheath 112 and sheath shuttle 167 isdistally positioned upon the system 110 in the stent attachment portion130 of the system 110. The constraining shuttle 165 of the handle 126are also positioned distally in a locked position and maintaining thestent 128 in a constrained position 140. As shown in FIG. 13B, in orderto deploy the stent 128, the user proximally moves the sheath shuttle167, which uncovers the stent 128. The user then unlocks theconstraining shuttle 165 of the handle 126 and moves the constrainingshuttle 165 in a proximal direction. The proximal movement of theconstraining shuttle 165 moves the stent from the constrained positionto the expanded position. Once the stent 128 is placed in the correctposition, the user may release the release wire 159 and deploy the stent128 within the vessel of the patient.

FIG. 14 illustrates a sectional view of an alternate embodiment of astent delivery system 210. The stent delivery system 210 includes aninner shaft 222 and an outer shaft 221. A stent 228 is positionable on astent region 230 of the inner shaft 222 at a distal portion 231 of thedelivery system 210. The stent 228 is shown in an expanded configuration266 in FIG. 14 where the stent 228 is expanded away from the inner shaft222. The distal constraining assembly 246 is in a second position andremain connected to the stent 228 but the longitudinal force on thestent 228 has been removed to allow the stent 228 to expand. This secondposition of the proximal and distal constraining member 244, 246 ismanipulated in a proximal direction through the use of a handle 226attached to the system 210. The inner shaft 222 includes a first, suturelumen 234, a second lumen 272, a third lumen 274. As shown, the distalstent constraining arrangement 246 is disposed through the suture lumen234. A release wire 259 is disposed through the third lumen 274 and isengaged with a portion of the proximal and distal constrainingarrangements 244, 246 to anchor the proximal and distal constrainingarrangements 244, 246 to the inner tube 222. The stent delivery system210 may also include a guidewire extendable through the second lumen 272of the inner shaft 222 through a distal tip 241 at the distal portion231 of the delivery system 210. The outer shaft 221 includes a firstlumen 280 and a second lumen 282. The inner shaft 222 is concentricallypositioned within the first lumen 280 of the outer shaft 221. Theproximal stent constraining arrangement 244 is disposed through thesecond lumen 282 of the outer shaft 221. In this embodiment, theproximal constraining arrangement 244 and the distal constrainingarrangement 246 are positioned within different lumens and do notinterfere with one another. Thus, the proximal constraining arrangement244 and the distal constraining arrangement 246 can operateindependently from each other. With this embodiment, the proximalconstraining arrangement 244 and the distal constraining arrangement 246allow for the distal end 231 of the stent 228 and the proximal end 232of the stent 228 can be moved from the constrained position 240 to theexpanded position 266 at different times and by different amounts.

FIG. 15 illustrates a cross-section through an outer shaft 221 of anembodiment of the present invention. In this embodiment, the system 210is provided in an over-the-wire configuration. In this over the wireconfiguration, the cross-section throughout the outer tube 221 is thesame throughout its length. The outer tube 221 includes a first lumen280 and a second lumen 282. The first lumen 280 and the second lumen 282are disposed through the entire length of the outer tube 221. The firstlumen 280 is provided to receive at least a portion of the distalrestraining arrangement 244. The first lumen 280 may be used tofacilitate reception of the inner shaft 222. Each of the first lumen 280and the second lumen 282 are accessible from the proximal end of theouter shaft 221. Exemplary materials for forming the outer shaft 221include, but are not limited to, metal alloys such as stainless steel,tantalum or its alloys, tungsten, platinum, gold, copper, palladium,rhodium, or a superelastic alloys, such as nitinol or polymers that canbe provided with sufficient shore hardness, such as Pebax, Peek,polyimide, liquid crystal polymers (LCP) such as Vectran, polyethylene,polyethylene terephthalate and Nylon. In alternative embodiments, theouter tube 221 may further include additional lumens.

FIG. 16 is a sectional view of an embodiment of the present invention.The stent delivery system 310 includes an inner shaft 322 and a handle326 at a proximal portion 327 of the system 310. A stent retainingregion 330 is present at the proximal end 327 of the system in order toprovide an area for placement of a stent for use with the system 310.The inner shaft 322 includes a first, suture lumen, a second lumen, anda third lumen. The outer shaft 321 includes a first lumen and a secondlumen 382. The inner shaft 322 is disposed within the second lumen 382of the outer shaft 321 such that the inner shaft 322 is concentric withthe outer shaft 321. The distal loops 348, 350 of the distalconstraining arrangement 346 are disposed within the suture lumen of theinner shaft 322. The proximal loops of the proximal constrainingarrangement 344 are disposed within the first lumen of the outer shaft.The handle 326 is disposed about the outer surface of the outer shaft321 and includes a hub 363, a sheath shuttle 367, and a constrainingshuttle 365. A sheath 312 is operably connected to the sheath shuttle367 of the handle 326. As shown, the proximal loops of the proximalconstraining arrangement 344 exit the suture lumen of the inner shaft322 and engage with at least a portion of the constraining shuttle 365.Similarly, the distal loops of the distal constraining arrangement 344exit the first lumen 380 of the outer shaft 321 and are operablyconnected with at least a portion of the constraining shuttle 365. Inthis embodiment, the proximal loops of the proximal constrainingarrangement 344 and the distal loops of the distal constrainingarrangement 346 are operably connected to a brake assembly 390 disposedwithin the housing of the constraining shuttle 365. The brake assembly390, in this embodiment, comprises a washer 392 and a break spring 394disposed about the surface of the outer shaft 321 of the system 310. Thespring 394 of the brake assembly 390 keeps the washer 392 at an anglewith respect to the outer shaft 321 and keeps the brake washer 392 readyto engage with the shaft upon activation of the brake assembly 390. Thisarrangement prevents the brake 390 from failing to engage and thisarrangement decreases the time taken for the break to engage uponactivation.

In one embodiment, the distal loops of the distal constrainingarrangement 346 are positioned underneath the brake assembly 390 and areattached to the constraining shuttle 365 at the proximal end 327 of thesystem 310. The proximal loops of the proximal constraining arrangement344 maybe looped around the brake assembly 390 in order to accommodatethe additional length required in order to make the proximalconstraining arrangement 344 operable with this embodiment of the brakeassembly 390. In this embodiment, the distal loops of the distalconstraining arrangement 346 may be pulled proximally up to three timesfurther then the proximal loops of the proximal constraining arrangement344 upon operation of the constraining shuttle 365 of the handle 326 inthe proximal direction. One of ordinary skill in the art will understandthat alternative arrangements may be utilized with this aspect of thepresent invention. As will be as will be discussed, the brake assembly390 allows for staged deployment of the proximal end of a stent and thedistal end of a stent. A release wire is disposed through the secondlumen and is engaged with a portion of the proximal and distalconstraining arrangements 344, 346 to anchor the proximal and distalconstraining arrangements 344, 346 to the inner tube 322.

FIGS. 17A-17C illustrate operation of this embodiment of the system 310of the present invention. Referring to FIG. 17 A, the sheath shuttle 367has been moved in a proximal direction and in abutting relation with thehub 363 of the handle 326. Upon moving the sheath shuttle 367 in theproximal direction, the sheath attached to the sheath shuttle 367 isretracted in the proximal direction and uncovers the stent. In thisposition, the stent is still in the constrained configuration 340. Theconstraining shuttle 365 of the handle 326 is in a distal position withrespect to the hub 363 of the handle 326. In this distal position, theproximal constraining arrangement 344 and the distal constrainingarrangement 346 remain in the taut configuration which maintains thestent in the collapsed configuration 340. In some embodiments, thesystem 310 may include a locking apparatus to maintain the constrainingshuttle 365 in this distal position. In these embodiments, the lockassembly may prevent premature deployment of the stent prior to properpositioning of the stent within the target lumen of the patient. Asshown by FIG. 17A, the brake washer 392 and the brake spring 394 areengaged. When the brake assembly 390 is engaged, the proximalconstraining arrangement 344 and the distal constraining arrangement 346are maintained in the taut configuration. This brake assembly 390 alsoprevents premature deployment expansion of the stent prior to properpositioning of the stent within the lumen of the patient.

Referring now to FIG. 17 B, the constraining shuttle 365 has been movedin a proximal direction with respect to the hub 363 of the handle 326.The proximal movement of the constraining shuttle 365 disengages thebrake assembly 390. In this embodiment, the washer 392 of the brakeassembly 390 is pulled into a vertical configuration. In addition, thebrake spring 394 of the brake assembly 390 is compressed, which allowsfor the washer to be positioned vertically within the body of theconstraining shuttle 365. Upon disengagement, the entire brake assembly390 is able to move in conjunction with the movement of the constrainingshuttle 365 of the handle 326. This movement of the brake assembly 390,allows for the proximal constraining arrangement 344 and the distalconstraining arrangement 346 to move in the proximal direction.

Referring now to FIG. 17 C, the constraining shuttle 365 has been fullymoved in the proximal direction with respect to the hub 363 of thehandle 326. As shown the brake assembly 390 has also been moved in theproximal direction. In this position, the stent 328 is now moved fromthe constrained configuration 340 to the expanded configuration 366. Inthis embodiment, this proximal movement of the proximal constrainingarrangement 344 and the distal constraining arrangement 346 release thestent 328 from the constrained configuration 340 to the expandedconfiguration 366. In alternative embodiments, the system 310 may allowfor staged a release of the distal end and the proximal end of thestent. The stent, while in the expanded configuration, is stillconnected to the system 310 by the proximal constraining arrangement 344and the distal constraining arrangement 346. The stent 328 may berepeatedly moved between the constrained configuration and the expandedconfiguration by manipulating the proximal constraining arrangement 344and the distal constraining arrangement 346 either in a proximaldirection or a distal direction until the stent 328 is properlypositioned through the use of the constraining shuttle 365. Upon movingthe constraining shuttle 365 in the distal direction the distal loops ofthe distal constraining configuration 346 are pulled first, whichconstrains the distal end of the stent prior to the proximal end of thestent which allows for any additional material of the loops of theproximal constraining arrangement 344 to also be pulled by theconstraining handle 365. Upon removal of any slack material of theproximal constraining arrangement 344, the distal end and the proximalend of the stent are constrained simultaneously.

FIG. 18 illustrates of an alternative embodiment of a handle assembly426 of a stent delivery system 410. The handle assembly 426 includes ahub 463, a sheath shuttle 467, a constraining shuttle 465, and a handleback stop 468 positioned on a proximal end of the handle assembly 426. Afirst conduit 484 and a second conduit 486 of the hub 463 are engagedwith the handle back stop 468. In a particular embodiment, as shown inFIG. 18, the first conduit 484 and the second conduit 486 arecylindrical tubules. An outer shaft 421 is disposed through a lumen ofthe first conduit 484. As shown, the sheath shuttle 467 is engaged withan outer surface of the first conduit 484 and is configured to travellongitudinally with respect to the first conduit 484. The sheath 412 isoperably connected to the sheath shuttle 467 of the handle 426. In someembodiments, the sheath 412 may include additional features, including,but not limited to, the ability to be torn away from the device or theability to crumple. The constraining shuttle 465 is engaged with anouter surface of the second conduit 484 and is configured to travellongitudinally with respect to the second conduit is disposed on thesecond conduit 484. As shown in the embodiment of FIG. 18, theconstraining shuttle 465 is positioned distal to the sheath shuttle 467.In this particular embodiment, the constraining shuttle 465 isconfigured to move proximally following movement of the sheath shuttle467 in the proximal direction. In alternative embodiments, theconstraining shuttle 465 and the sheath shuttle 467 may be configuredsuch that the constraining shuttle 465 may be moved independent of themovement of the sheath shuttle 467.

FIG. 19 is a schematic view of an embodiment of the system 410 and thehandle assembly 426. The handle assembly 426 includes a hub 463, asheath shuttle 467, a constraining shuttle 465, and a handle back stop468 positioned on a proximal end of the handle assembly 326. A firstconduit 484 and a second conduit 486 of the hub 463 are engaged with thehandle back stop 468. The first conduit 484 and the second conduit 486each have a lumen disposed therethrough. An outer shaft 421 and an innershaft 422 are disposed through a lumen of the first conduit 484. Asshown, proximal loops of a proximal constraining arrangement 444 exit alumen of the inner shaft 422 and engage with at least a portion of theconstraining shuttle 465. Similarly, distal loops of the distalconstraining arrangement 446 exit a lumen of the outer shaft 421 and areoperably connected with at least a portion of the constraining shuttle465. In this embodiment, the proximal loops of the proximal constrainingarrangement 444 and the distal loops of the distal constrainingarrangement 446 are operably connected to a brake assembly 490 disposedwithin the housing of the constraining shuttle 465. A pathway 469connecting the first conduit 484 and the second conduit 486 is providedwithin the handle back stop 468 to allow the proximal loops of theproximal constraining arrangement 444 and the distal loops of the distalconstraining arrangement 446 to pass from the outer shaft 421, innershaft 422, and the first conduit 484 into a lumen of the second conduit486. The proximal loops of the proximal constraining arrangement 444 andthe distal loops of the distal constraining arrangement 446 enter intothe lumen of the second conduit 486 through a port 487. The brakeassembly 490, in this embodiment, comprises a washer 492 and a breakspring 494 disposed about the surface of the outer shaft 421 of thesystem 410. The break spring 494 of the brake assembly 490 keeps thewasher 492 at an angle with respect to the outer shaft 421 and keeps thebrake washer 492 ready to engage with the shaft upon activation of thebreak. This arrangement prevents the brake from failing to engage anddecreases the time taken for the break to engage upon activation.

In one embodiment, the distal loops of the distal constrainingarrangement 446 are positioned underneath the brake assembly 490 and areattached to the constraining shuttle 465 at the proximal end. Theproximal loops of the proximal constraining arrangement 444 maybe loopedaround the brake assembly 490 in order to accommodate the additionallength required in order to make the proximal constraining arrangement444 operable with this embodiment of the handle brake assembly 490. Inthis embodiment, the distal loops of the distal constraining arrangement446 may be pulled proximally up to three times further then the proximalloops of the proximal constraining arrangement 444 upon operation of theconstraining shuttle 465 of the handle 426 in the proximal direction.One of ordinary skill in the art will understand that alternativearrangements may be utilized with this aspect of the present invention.As will be as will be discussed, the brake arrangement 490 allows forstaged deployment of the proximal end of a stent and the distal end of astent. A release wire may be disposed in through the second lumen 472and is engaged with a portion of the proximal and distal constrainingarrangements 444, 446 to anchor the proximal and distal constrainingarrangements 444, 446 within the system 410.

As shown, the sheath shuttle 467 is engaged with an outer surface of thefirst conduit 484 and the sheath 412 is operably connected to the sheathshuttle 467 of the handle 426. The constraining shuttle 465 is engagedwith an outer surface of the second conduit 484 and is configured totravel longitudinally with respect to the second conduit 484. The sheathshuttle 467 includes an opening 471. The opening 471 allows the sheathshuttle 467 to move along the first conduit 484 while not interferingwith the constraining shuttle 465 and the second conduit. Likewise, theconstraining shuttle 465 also includes an opening 473. The opening 473allows the constraining shuttle 465 to move along the second conduit 486while not interfering with the sheath shuttle 467 and the first conduit484.

FIGS. 20A and 20B illustrate operation of this embodiment of the system410 of the present invention. Referring to FIG. 20 A, the sheath shuttle465 has been moved in a proximal direction and in abutting relation withthe handle back stop 468 of the handle 426. Upon moving the sheathshuttle 467 in the proximal direction, the sheath 412 attached to thesheath shuttle 467 is retracted in the proximal direction and uncoversthe stent 428. In this position, the stent 428 is still in theconstrained configuration 440. The constraining shuttle 465 of thehandle 426 is in a distal position with respect to the hub 463 of thehandle 426. In this distal position, the proximal constrainingarrangement 444 and the distal constraining arrangement 446 remain inthe taut configuration which maintains the student in the collapsedconfiguration. In some embodiments, the system 410 may include a lockingapparatus to maintain the constraining shuttle in this distal position.In these embodiments the lock may prevent premature deployment of thestent prior to proper positioning of the stent within the target lumenof the patient. As shown by FIG. 20A, the washer 492 and the brakespring 494 are engaged. When the brake assembly 490 is engaged, theproximal constraining arrangement 444 and the distal constrainingarrangement 446 are maintained in the taut configuration. This brakeassembly 490 also prevents premature deployment expansion of the stent428 prior to proper positioning of the stent 428 within the lumen of thepatient.

Referring now to FIG. 20B, the constraining shuttle 465 has been fullymoved in the proximal direction with respect to the hub 463 of thehandle 426. The proximal movement of the constraining shuttle 465 thisengages the brake assembly 490. In this embodiment, the washer 494 ofthe brake assembly 490 is pulled into a vertical configuration. In thisposition, the stent is now moved from the constrained configuration 440to the expanded configuration 464. In this embodiment, this proximalmovement of the proximal constraining arrangement 444 and the distalconstraining arrangement 446 release the stent from the constrainedconfiguration 440 to the expanded configuration 466. In alternativeembodiments, the system 410 may allow for staged a release of the distalend and the proximal end of the stent. The stent, while in the expandedconfiguration, is still connected to the system 410 by the proximalconstraining configuration 444 and the distal constraining configuration446. The stent may be repeatedly moved between the constrainedconfiguration 440 and the expanded configuration 466 by moving theconstraining shuttle 465 distally with respect to the hub 463 of thehandle 426. Upon moving the constraining shuttle 465 in the distaldirection the distal loops 448, 450 of the distal constrainingconfiguration 446 are pulled first, which constrains the distal end ofthe stent prior to the proximal end of the stent which allows for anyadditional material of the proximal loops of the proximal constrainingarrangement 444 to also be pulled by the constraining handle 465. Uponremoval of any slack material of the proximal constraining arrangement444, the distal end 433 and the proximal end 432 are constrainedsimultaneously.

FIG. 21 illustrates of schematic view of an alternative embodiment of ahandle assembly 526 of a stent delivery system 510. The stent deliverysystem 510 includes an inner shaft 522, outer shaft 521, and a handle526 at a proximal portion of the system 510 having a handle back stop568. A stent retaining region 530 is present at the distal end 527 ofthe system 510 in order to provide an area for placement of a stent foruse with the system 510. The inner shaft 522 includes a suture lumen, asecond lumen, and a third lumen. The outer shaft 521 includes a firstlumen, and a second lumen. The inner shaft 522 may be disposed withinthe first lumen of the outer shaft 521 such that the inner shaft 521 isconcentric with the outer shaft 521. The distal loops of the distalconstraining arrangement 546 are disposed within the suture lumen of theinner shaft 522. The proximal loops of the proximal constrainingarrangement 544 are disposed within the first lumen of the outer shaft521. The handle assembly 526 is disposed about the outer surface of theouter shaft 521 and includes a hub 563, a sheath shuttle 567, and aconstraining shuttle 565. A sheath 512 is operably connected to thesheath shuttle 567 of the handle 526. The constraining shuttle 565comprises an outer shuttle 576 and an inner shuttle 578. As shown, theproximal loops of the proximal constraining arrangement 544 exit thefirst lumen of the outer shaft 521 and engage with at least a portion ofthe constraining shuttle 565. Similarly, the distal loops of the distalconstraining arrangement 546 exit the inner shaft 522 and are operablyconnected with at least a portion of the constraining shuttle 565. Inthis embodiment, the proximal loops of the proximal constrainingarrangement 544 are operably connected to a brake assembly 590 disposedwithin the housing of the constraining shuttle 565. The brake assembly590, in this embodiment, comprises a washer 592 and a break spring 594disposed about the surface of the outer shaft 521 of the system 510. Thespring 594 of the brake assembly 590 keeps the washer 592 at an anglewith respect to the outer shaft 521 and keeps the brake washer 592 readyto engage with the shaft 521 upon activation of the brake assembly 590.This arrangement prevents the brake from failing to engage and thisarrangement decreases the time taken for the brake to engage uponactivation. The distal loops of the distal constraining arrangement 546are connected to the inner shuttle 578. A compressed spring 579 isengaged with the inner shuttle 578 and maintains the distal end of thestent in the compressed position.

FIGS. 22A and 22B illustrate operation of this embodiment of the system510 of the present invention. Referring to FIG. 22 A, the sheath shuttle567 has been moved in a proximal direction and in abutting relation withthe handle back stop 568 of the handle 526. Upon moving the sheathshuttle 567 in the proximal direction, the sheath 512 attached to thesheath shuttle 565 is retracted in the proximal direction and uncoversthe stent. In this position, the stent is still in the constrainedconfiguration. The constraining shuttle 565 of the handle 526 is in aproximal position with respect to the hub 563 of the handle 526. In thisproximal position, the proximal constraining arrangement 544 and thedistal constraining arrangement 546 remain in the taut configurationwhich maintains the stent in the collapsed configuration. In someembodiments, the system 510 may include a locking apparatus to maintainthe constraining shuttle 565 in this distal position. In theseembodiments, the lock may prevent premature deployment of the stentprior to proper positioning of the stent within the target lumen of thepatient.

Referring now to FIG. 22 B, the constraining shuttle 565 has been fullymoved in the distal direction with respect to the hub of the handle. Thedistal movement of the constraining shuttle 565 this engages the brakeassembly 590. In this embodiment, the washer 594 of the brake assembly590 is pulled into a vertical configuration. In this position, the stentis now moved from the constrained configuration to the expandedconfiguration. In this embodiment, this distal movement of the proximalconstraining arrangement 544 and the distal constraining arrangement 546release the stent from the constrained configuration 540 to the expandedconfiguration 566. In alternative embodiments, the system 510 may allowfor staged a release of the distal end and the proximal end of thestent. The stent, while in the expanded configuration 566, is stillconnected to the system 510 by the proximal constraining configuration544 and the distal constraining configuration 546. The stent may bemoved from the expanded configuration to the constrained configurationby moving the constraining shuttle 565 in the proximal direction withrespect to the hub 563 of the handle assembly 526. Upon moving theconstraining shuttle 565 in the proximal direction the distal loops ofthe distal constraining configuration 546 are pulled first, whichconstrains the distal end of the stent prior to the proximal end of thestent which allows for any additional material of the proximal loops ofthe proximal constraining arrangement 544 to also be pulled by theconstraining handle 565. Upon removal of any slack material of theproximal constraining arrangement 544, the distal end and the proximalend of the stent are constrained. In this embodiment, the distal end ofthe stent is constrained prior to the proximal end of the stent. Due tothe distal constraining arrangement 546 traveling a different path thanthe proximal constraining arrangement 544 and the sequence ofconstraining the distal end of the stent prior to the proximal end ofthe stent, the amount of force needed to constrain the stent may bereduced.

FIG. 23 illustrates of schematic view of an alternative embodiment of ahandle assembly 626 of a stent delivery system 610. The stent deliverysystem 610 includes an inner shaft 622 and a handle 626 at a proximalportion 627 of the system 610, and a handle back stop 668. A stentretaining region 630 is present at the proximal end 627 of the system610 in order to provide an area for placement of a stent for use withthe system 610. The inner shaft 622 includes a suture lumen, a secondlumen, and a third lumen. The outer shaft 621 includes a first lumen,and a second lumen. The inner shaft 622 is disposed within the secondlumen of the outer shaft 621 such that the inner shaft 622 is concentricwith the outer shaft 621. The distal loops of the distal constrainingarrangement 646 are disposed within the suture lumen of the inner shaft622. The proximal loops of the proximal constraining arrangement 644 aredisposed within the outer shaft 621. The handle assembly 626 is disposedabout the outer surface of the outer shaft 621 and includes a hub 663, asheath shuttle 667, and a constraining shuttle 665. A sheath 612 isoperably connected to the sheath shuttle 667 of the handle 626. Asshown, the proximal loops of the proximal constraining arrangement 644exit the lumen of the inner shaft 621 and engage with at least a portionof the constraining shuttle 665. Similarly, the distal loops of thedistal constraining arrangement 646 exit the lumen of the outer shaft621 and operably connected with at least a portion of the constrainingshuttle 665. In this embodiment, the proximal loops of the proximalconstraining arrangement 644 are operably connected to a first brakeassembly 690 disposed within the housing of the constraining shuttle665. Likewise, the distal loops of the distal constraining arrangement646 are operably connected to a second brake assembly 691 disposedwithin the housing of the constraining shuttle 665. The second brakeassembly 691 is positioned proximal to the first brake assembly 690. Thefirst brake assembly 690, in this embodiment, comprises a washer 692 anda break spring 694 disposed about the surface of the outer shaft 621 ofthe system 610. The break spring 694 of the first brake assembly 690keeps the washer 692 at an angle with respect to the outer shaft 621 andkeeps the brake washer 692 ready to engage with the outer shaft 621 uponactivation of the first brake assembly 690. This arrangement preventsthe first brake assembly 690 from failing to engage and this arrangementdecreases the time taken for the first brake assembly 690 to engage uponactivation. The second brake assembly 691 also comprises a washer 693and a break spring 695 disposed about the surface of the outer shaft 621of the system 610. The second break assembly 691 further includes aprojection 696 extending from the washer 693. A leaf spring 697 andcollar 698 are positioned within the interior surface of the handleassembly 626. The projection 696 of the second brake assembly 691 isconfigured to allow the leaf spring 697 to slide over second brakeassembly 691 when the constraining shuttle 665 is moved distally andconfigured to engage the leaf spring 697 when the constraining shuttle665 is moved proximally.

FIGS. 24A-24C illustrate operation of this embodiment of the system 610of the present invention. Referring to FIG. 24 A, the sheath shuttle 667has been moved in a proximal direction and in abutting relation with thehandle back stop 668 of the handle assembly 626. Upon moving the sheathshuttle 667 in the proximal direction, the sheath 612 attached to thesheath shuttle 667 is retracted in the proximal direction and uncoversthe stent 628. In this position, the stent is still in the constrainedconfiguration 640. The constraining shuttle 665 of the handle assembly626 is in a proximal position with respect to the hub 663 of the handle665. In this proximal position, the proximal constraining arrangement644 and the distal constraining arrangement 646 remain in the tautconfiguration which maintains the stent in the collapsed configuration640. In some embodiments, the system 610 may include a locking apparatusto maintain the constraining shuttle 665 in this distal position. Inthese embodiments the lock may prevent premature deployment of the stentprior to proper positioning of the stent within the target lumen of thepatient. As shown by FIG. 24A, the first brake assembly 690 and thebrake spring 692 are engaged. When the first brake assembly 690 isengaged, the proximal constraining arrangement is maintained in the tautconfiguration. Likewise, the second brake assembly 691 and the brakespring 693 are engaged. When the second brake assembly 691 is engaged,the distal constraining arrangement is maintained in the tautconfiguration. This first brake assembly 690 and the second brakeassembly 691 also prevent premature deployment expansion of the stent628 prior to proper positioning of the stent 628 within the lumen of thepatient.

Referring now to FIG. 24 B, the constraining shuttle 665 has been fullymoved in the distal direction with respect to the hub 663 of the handle.The distal movement of the constraining shuttle 665 disengages thesecond brake assembly 691. The proximal end of the constraining shuttle665 disengages the second brake assembly 691 and unlocks it, whichcauses the second brake assembly 691 to move in the distal direction.This distal movement of the second brake assembly 691 releases thetension on the distal constraining arrangement 646 and the distal end ofthe stent is expanded. As the constraining shuttle 665 continues to movein the distal direction, the second brake assembly 691 moves along withit and comes into contact with the first brake assembly 690 anddisengages it. The disengaged first brake assembly 690 moves in thedistal direction and the tension on the proximal constrainingarrangement 644 and the proximal end of the stent is expanded. In thisembodiment, this distal movement of the proximal constrainingarrangement 644 and the distal constraining arrangement 646 release thestent from the constrained configuration to the expanded configuration.In alternative embodiments, the system 610 may allow for staged arelease of the distal end and the proximal end of the stent. The stent,while in the expanded configuration 646, is still connected to thesystem 610 by the proximal constraining configuration 644 and the distalconstraining configuration 646. The stent may be moved from the expandedconfiguration to the constrained configuration by moving theconstraining shuttle 665 in the proximal direction with respect to thehub 663 of the handle.

FIG. 24C illustrates how the stent may be moved from the expandedconfiguration 666 to the constrained configuration 640. Upon moving theconstraining shuttle 665 in the proximal direction, the leaf spring 697engages the projection 696 of the second brake assembly 691 and moves itin the proximal direction. The leaf spring and the collar applysufficient force to move the second brake assembly 691 in the proximaldirection. This proximal movement of the second brake assembly 691causes the distal loops of the distal constraining configuration 646 tobe pulled taut, which constrains the distal end 633 of the stent priorto the proximal end of the stent. The second brake assembly 691 is alsoengaged, which prevents the distal end 633 of the stent from beingreleased from the constrained position 640. As the constraining shuttle665 is moved further in the proximal direction, the first brake assembly691 is also pulled proximally. Upon removal of any slack material of theproximal constraining arrangement 644, the distal end and the proximalend are constrained. When both the distal end and the proximal end ofthe stent are constrained, the leaf spring 697 is released from thesecond brake assembly 691, as the amount of force of constraining sheath665 exceeds the force of the leaf spring 697. In this embodiment, thedistal end of the stent is constrained prior to the proximal end of thestent.

FIG. 25 illustrates a cross-section through an alternative outer shaft721 of an embodiment of the present invention. In this embodiment, thesystem 710 is provided in an over-the-wire configuration. In this overthe wire configuration, the cross-section throughout the outer tube 721is the same throughout its length. The outer tube 721 includes a firstlumen 780, a second lumen 782, and a third lumen 784. The first lumen780, a second lumen 782, and a third lumen 784 are disposed through theentire length of the outer tube 721. The first lumen 780 may be used tofacilitate the introduction of a medical device, such as a guidewire.The second lumen 782 and third lumen 784 is provided to receive oneproximal loop, respectively, of the proximal constraining member 744.Each of first lumen 780, a second lumen 782, and a third lumen 784, areaccessible from the proximal end of the outer shaft 721. Exemplarymaterials for forming the shaft include, but are not limited to, metalalloys such as stainless steel, tantalum or its alloys, tungsten,platinum, gold, copper, palladium, rhodium, or a superelastic alloys,such as nitinol or polymers that can be provided with sufficient shorehardness, such as Pebax, Peek, polyimide, liquid crystal polymers (LCP)such as Vectran, polyethylene, polyethylene terephthalate and Nylon. Inalternative embodiments, the inner tube may further include additionallumens. In one embodiment, a fourth lumen may be included within theinner tube. In this embodiment, the fourth lumen may be used to providea conduit for a second restraining member for the proximal constrainingmember of the stent.

FIG. 26 illustrates a perspective view of an alternative embodiment of ahandle assembly 826 of a stent delivery system 810. The stent deliverysystem 810 includes an inner shaft 822 and a handle 826 at a proximalportion of the system 810. The inner shaft 822 includes a suture lumen,a second lumen, and a third lumen. The outer shaft 821 includes a firstlumen and a second lumen. The inner shaft 822 is disposed within theouter shaft 821 such that the inner shaft 822 is concentric with theouter shaft 821. The distal loops of the distal constraining arrangement846 are disposed within the suture lumen 834 of the inner shaft 822. Theproximal loops of the proximal constraining arrangement 844 are disposedwithin the first lumen 880 of the outer shaft 821. The handle assembly826 is disposed about the outer surface of the outer shaft 821 andincludes a hub 863, a sheath shuttle 867, and a constraining shuttle865. A sheath 812 is operably connected to the sheath shuttle 867 of thehandle 826. As shown, the proximal loops of the proximal constrainingarrangement 844 exit the first lumen 880 of the outer shaft 821 andengage with at least a portion of the constraining shuttle 865.Similarly, the distal loops of the distal constraining arrangement 846exit the suture lumen 834 of the inner shaft 822 and operably connectedwith at least a portion of the constraining shuttle 865. In thisembodiment, the proximal loops of the proximal constraining arrangement844 are operably connected to proximal shuttle 878 disposed within thehousing of the constraining shuttle 865. Likewise, the distal loops ofthe distal constraining arrangement 846 are operably connected to adistal shuttle 876 disposed within the housing of the constrainingshuttle 865. The proximal shuttle 876 and the distal shuttle 876 areconfigured to engage with the constraining shuttle 865 and each havededicated tracks to allow for longitudinal movement with respect to theconstraining shuttle 865. As shown, the constraining shuttle 865 hasbeen moved in the distal direction with respect to the hub 863 of thehandle 826. The distal movement of the constraining shuttle 865 firstengages distal shuttle 876 and moves it in the distal direction. In thisposition, the stent 828 is now moved from the constrained configuration840 to the expanded configuration 866. In this embodiment, this distalmovement of the distal shuttle 876 releases the distal end 833 of thestent 828 from the constrained configuration 840 to the expandedconfiguration 866. Once the distal end 833 of the stent 828 is deployed,the constraining shuttle 865 is continually moved in the distaldirection and disengages from the proximal shuttle 878. Subsequently,the constraining shuttle 865 engages the proximal shuttle 878 and movesit in the distal direction. The distal movement of the proximal shuttle878 releases proximal end of the stent from the constrainedconfiguration 840 to the expanded configuration 866. The stent, while inthe expanded configuration, is still connected to the system 810 by theproximal constraining arrangement 844 and the distal constrainingarrangement 846.

FIG. 27 illustrates operation of this embodiment of the handle 826 ofthe present invention. The constraining shuttle 865 of the handle 826 isin a distal position with respect to the hub 863 of the handle 826. Inthis distal position, the proximal constraining arrangement 844 and thedistal constraining arrangement 846 remain in the taut configurationwhich maintains the stent in the collapsed configuration 840. In someembodiments, the system 810 may include a locking apparatus to maintainthe constraining shuttle 865 in this distal position. In theseembodiments the lock may prevent premature deployment of the stent priorto proper positioning of the stent within the target lumen of thepatient. As shown by FIG. 27, the proximal shuttle 878 and distalshuttle 876 are also positioned proximally and in locked position. Aratchet mechanism may be added to prevent the user from changing thedirection of movement of the shuttle during operation.

The stent may be moved from the expanded configuration 866 to theconstrained configuration 868 by moving the constraining shuttle 865 inthe proximal direction with respect to the hub 863 of the handle 826.Upon moving the constraining shuttle 865 in the proximal direction thedistal shuttle 868 is engaged and the distal loops of the distalconstraining configuration 846 are pulled first, which constrains thedistal end of the stent prior to the proximal end of the stent Furthermovement of the constraining shuttle 865 in the proximal direction alsoengages the proximal shuttle 878 and begins to pull the proximal end ofthe stent taut. Upon removal of any slack material of the proximalconstraining arrangement 844, the distal end and the proximal end of thestent are constrained. In this embodiment, the distal end of the stentis constrained prior to the proximal end of the stent. Due to the distalconstraining arrangement 846 traveling a different path than theproximal constraining arrangement 844 and the sequence of constrainingthe distal end of the stent prior to the proximal end of the stent, theamount of force needed to constrain the stent may be reduced.

Throughout this specification various indications have been given as topreferred and alternative examples and aspects of the invention.However, the foregoing detailed description is to be regarded asillustrative rather than limiting and the invention is not limited toany one of the provided aspects. It should be understood that it is theappended claims, including all equivalents, that are intended to definethe spirit and scope of this invention.

The invention claimed is:
 1. A stent delivery system, comprising, anelongate shaft including a proximal portion, a distal portion, at leastone lumen extending at least partially therethrough, a stent receivingportion on the distal portion of the elongate shaft, and an openingdisposed on the elongate shaft and positioned distal to the stentreceiving portion; a stent positioned on the stent receiving portion ofthe elongate shaft, the stent having a first configuration and a secondconfiguration; a proximal constraining member positioned on a proximalend of the stent; a distal constraining member positioned on a distalend of the stent; a restraining member disposed throughout a length ofthe elongate shaft and releasably engaged with the distal constrainingmember, the restraining member having a proximal end and a distal end; arelease wire disposed through the elongate shaft and releasably engagedwith the proximal constraining member and the distal end of therestraining member; wherein when the stent is in the firstconfiguration, the restraining member applies an axial mechanical forceto the distal constraining member, and wherein the restraining memberextends proximally from the opening of the elongate shaft to engage thedistal constraining member.
 2. The stent delivery system of claim 1,further comprising a handle operably connected to the restraining memberfor moving the distal constraining member from a first position and asecond position to move the stent between the first configuration andthe second configuration.
 3. The stent delivery system of claim 1,wherein the proximal constraining member comprises a pair of proximalgrasping loops engaged with the proximal end of the stent and the distalconstraining member comprises a pair of distal grasping loops engagedwith the distal end of the stent.
 4. The stent delivery system of claim3, wherein the pair of proximal grasping loops and the pair of distalgrasping loops comprise suture material.
 5. The stent delivery system ofclaim 3, wherein the distal end of the distal constraining member isreleasably anchored by the restraining member in a position distal tothe stent receiving portion of the elongate shaft.
 6. The stent deliverysystem of claim 1, wherein the elongate shaft further comprises a firstlumen and a second lumen.
 7. The stent delivery system of claim 6,wherein the restraining member is disposed at least partially within thefirst lumen and the release wire is disposed within the second lumen. 8.The stent delivery system of claim 1, wherein the proximal constrainingmember is releasably anchored by the release wire in a position proximalto the stent receiving portion of the elongate member.
 9. The stentdelivery system of claim 1, further comprising a sheath removablypositionable over the stent and a portion of the elongate shaft.
 10. Thestent delivery system of claim 1, wherein the distal end of the stent iscontinually moveable from the first configuration to the secondconfiguration.
 11. A method of implanting a stent in a patient's lumen,the method comprising: inserting a distal portion of a stent deliverysystem into a lumen of a patient, the stent delivery system comprising:an elongate shaft including a proximal portion, a distal portion, atleast one lumen extending at least partially therethrough, a stentreceiving portion on the distal portion of the elongate shaft, and anopening disposed on the elongate shaft and positioned distal to thestent receiving portion; a stent positioned on the stent receivingportion of the elongate shaft, the stent having a first configurationand a second configuration; a proximal constraining member positioned ona proximal end of the stent; a distal constraining member positioned ona distal end of the stent; a distal restraining member disposedthroughout the length of the elongate shaft and releasably engaged withthe distal constraining member, the distal restraining member having aproximal end and a distal end; wherein the distal restraining memberextends proximally from the opening of the elongate shaft to engage thedistal constraining member; a release wire is disposed through theelongate shaft and releasably engaged with the proximal constrainingmember and the distal end of the restraining member; holding the stentin the first configuration with longitudinal tensile force applied tothe stent by the restraining member and tensioning the stent fordelivery of the stent to an implant site; positioning the stent at theimplant site; expanding the distal end of the stent by manipulating therestraining member in a proximal direction and releasing longitudinalforce on the stent; and releasing the release wire and the distalconstraining member from the stent.
 12. The method of claim 11, furthercomprising reapplying the longitudinal force on the distal end of thestent to move the stent from the second configuration to the firstconfiguration by moving the distal restraining member in a distaldirection.
 13. The method of claim 11, further comprising providing ahandle cooperatively engaged with the release wire and the distalrestraining member.
 14. The method of claim 11, further comprisingproviding a removable sheath over the stent and a portion of theelongate shaft and withdrawing the removable sheath from the stent inthe patient's lumen so that the stent is exposed in the firstconfiguration.
 15. The method of claim 11, wherein the proximalconstraining member comprises a pair of proximal grasping loops engagedwith the proximal end of the stent and the distal constraining membercomprises a pair of distal grasping loops engaged with the distal end ofthe stent.
 16. The method of claim 15, wherein the pair of proximalgrasping loops and the pair of distal grasping loops comprise suturematerial.
 17. A stent delivery system, comprising, an elongate shaftincluding a proximal portion, a distal portion, at least one lumenextending at least partially therethrough, a stent receiving portion onthe distal portion of the elongate shaft, and an opening disposed on theelongate shaft and positioned distal to the stent receiving portion; asheath positioned longitudinally around the elongate shaft, the elongateshaft extending coaxially at least partially within the lumen of thesheath, the sheath moveably positionable relative to the elongate shaft;a stent positioned on the stent receiving portion of the elongate shaft,the stent having a first configuration and a second configuration; aproximal constraining member positioned on a proximal end of the stent;a distal constraining member positioned on a distal end of the stent,the distal constraining member comprising a pair of grasping loops; adistal restraining member disposed throughout the length of the elongateshaft and releasably engaged with the distal constraining member, thedistal restraining member having a proximal end and a distal end; arelease wire disposed through the elongate shaft and releasably engagedwith the proximal constraining member and the distal end of therestraining member wherein when the stent is in the first configuration,the distal restraining member applies an axial mechanical force to thedistal constraining member, and wherein the distal restraining memberextends proximally from the opening of the elongate shaft to engage thedistal constraining member.
 18. The stent delivery system of claim 17,further comprising a handle operably connected to the distal restrainingmember for moving the distal constraining member from a first positionand a second position to move the stent between the first configurationand the second configuration.